• Journal of the Korean Statistical Society
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• v.28 no.4
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• pp.469-478
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• 1999

We propose a Kolmogorov-Smirnov-type test for independence of paired failure times in the presence of independent censoring times. This independent censoring mechanism is often assumed in case-control studies. To do this end, we first introduce a process defined as the difference between the bivariate survival function estimator proposed by Wang and Wells (1997) and the product of the product-limit estimators (Kaplan and Meier (1958)) for the marginal survival functions. Then, we derive its asymptotic properties under the null hypothesis of independence. Finally, we assess the performance of the proposed test by simulations, and illustrate the proposed methodology with a dataset for remission times of 21 pairs of leukemia patients taken from Oakes(1982).

• Proceedings of the Korean Statistical Society Conference
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• 2000.11a
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• pp.33-38
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• 2000

Krishnamoorphy and Raghavarao(1993) invented exact binomial and asymptotically normal test procedures for truthful answering in the repeated randomized response models under the assumption that two repeated response measures are independent. Under the same assumption, Lakshmi and Raghavarao(1992) suggested asymptotic chi-square test for respondents' truthful answering in the same models. In this article we detect the factors and the conditions with which two response variables might be independent, and find the condition for independence in the repeated randomized response models with considering untruthful answer. But, the condition of independence make the randomized model no meaning. Under the assumption of conditional independence between two response variables, we can apply the same logical statements on deriving the tests for truthful answering in the repeated randomized response models as in Krishnamoorphy and Raghavarao(1993).

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1245-1255
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• 2015

In this paper, we investigated the major 8 companies of Korean stock market, and carried out the goodness of fit and independence tests. We found out the distributions of absolute returns are closed to compressed exponential distribution. The parameters are dominant that 1 < ${\beta}$ < 2, followed by ${\beta}=1$(exponential distribution) and ${\beta}=2$(normal distribution). Meanwhile, we assured that most of the absolute returns for major 8 companies have relevance to each other by chi-square independence test.

• Journal of the Korean Data and Information Science Society
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• v.15 no.1
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• pp.31-39
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• 2004

In this paper, we consider two components system which the lifetimes follow bivariate pareto model with bivariate random censored data. We assume that the censoring times are independent of the lifetimes of the two components. We develop large sample test for testing independence between two components. Also we present a simulation study which is the test based on asymptotic normal distribution in testing independence.

• Communications for Statistical Applications and Methods
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• v.29 no.4
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• pp.403-411
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• 2022

This article presents an independence test between pairs of interval censored failure times. The Mantel-Haenszel test is commonly applied to test the independence between two categorical variables accompanied with a strata variable. Hsu and Prentice (1996) applied a Mantel-Haenszel test to the sequence of 2 × 2 tables formed at the grids which are composed of failure times. In this article, due to unknown failure times, the suitable grid points should be determined and the status of failure and at risk are estimated at those grid points. We also consider a weighted test statistic to bring a more powerful test. Simulation studies are performed to evaluate the power of test statistics under finite samples. The method is applied to analyze two real data sets, mastitis data from milk cows and an age-related eye disease study.

• Journal of Korean Institute of Industrial Engineers
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• v.1 no.1
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• pp.99-103
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• 1975

A procedure for the test of independence of the observations and the null distribution are studied for a waiting-time distribution of the number of Bernoulli trials required to obtain a preassigned number of successes under Markov dependence. Selected critical values for the test statistic are tabulated.

• Journal of Korean Physical Therapy Science
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• v.2 no.3
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• pp.633-643
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• 1995

A longitudinal study of self-concept and functional independence in 22 adolescents with progressive muscular dystrophy is reported. 30 adolescents with progressive muscular dystrophy completed Korean Self-Concept Scale, Modified Barthel Index, and a questionnaire examining demographic and medical factors. Functional independence was measured by Modified Barthel Index. Two years later, 22 of the 30 adolescents with progressive muscular dystrophy completed same Korean Self-Concept Scale and Modified Barthel Index. Adolescents with progressive muscular dystrophy were not changed on self -concept scores between test and retest. At retest adolescents with progressive muscular dystrophy scored significantly lower than at test on Modified Barthel Index. Compared to scale norms, subjects had significantly lower Total Self, Physical Self, Social Self, Self Satisfaction, Self Behavior scores. Age, years of education, and functional independence were significantly related self-concept. Functional independence was significantly related years of education.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.51-63
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• 2001

We are interested in the conditional independence in sparse $2\tims2\tims$K tables with very rare cell counts. The most popular test is Cochran-Mantel-Haenszel statistic when sample sizes are moderately large enough to guarantee the chi-square approximation. We will consider jackknifing the CMH test and also suggest an approximate normal distribution for the standardized jackknifed CMH statistic. The main focus of this paper is to improve the chi-squared approximation to the CMH test by using the asymptotic normality of the jackknifed CMH test when sample sizes are very sparse but K and N$\infty$. The performance of the proposed jackknifed test, in the sense of significance level control and power, will be compared with that of the CMH test through a Monte Carlo study.

• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.327-333
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• 2006

In this paper, we consider the Bayesian hypotheses testing for independence in bivariate exponential model. In Bayesian testing problem, we use the noninformative priors for parameters which are improper and are defined only up to arbitrary constants. And we use the recently proposed hypotheses testing criterion called the fractional Bayes factor. Also we give some numerical results to illustrate our results.

• PNF and Movement
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• v.17 no.1
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• pp.31-39
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• 2019

Purpose: Cognitive function is a main concern for rehabilitation progression in individuals who have sustained brain damage, even among those whose motor function has returned after brain damage. The purpose of this study was to investigate how cognitive impairment relates to functional independence in postural stability and gait performance in patients with chronic hemiparetic stroke. Methods: This was an observational design in an outpatient rehabilitation hospital. Twenty-eight adults with chronic hemiparetic stroke, receiving a course in an outpatient rehabilitation program, participated in this study. They were divided into two groups (i.e., non-cognitive impairment and cognitive impairment groups) via a cut-off score of 23 or less on a mini-mental state examination. Functional independence was assessed with the timed up-and-go test (TUG), 10-meter walk test (10mWT), five times sit-to-stand test (FTSST), Berg balance scale (BBS), and modified Barthel index (MBI). The independent t-test was used for statistical analysis when comparing the two groups. Results: The cognitive impairment group had less functional independence, balance, and gait performance than those of the non-cognitive impairment group had. The former also showed a statistically significant decrease in their TUG score, FTSST score, BBS score, and MBI score compared to the latter, but not in their 10mWT score (p<0.05). Although the non-cognitive impairment group walked faster than the cognitive impairment group did, that difference was not statistically significant (p>0.05). Conclusion: The results of this study suggest that cognitive impairment relates to functional independence in postural stability and the activities of daily living. In rehabilitation settings, cognitive impairment would be considered a major component in therapeutic rehabilitation to overcome the patients difficult physical problems and to treat for improving functional independence more after stroke.